Telegraph



(No Model) H. G. ROBBINS.

TELEGRAPH TRANSMITTER.

No. 449,174. Patented M41431, 1891.

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PATENT GEET CEQI HARRY G. ROBBINS, OF MINNEAPOLIS, MINNESOTA.-

TELEGRAPH-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 449,174, dated March 31, 1891.

I Application filed November 29, 1890. Serial No. 373,010. (No model.)

To coil whom it may concern:

Be it known that I, HARRY G. ROBBINS, of Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain Improvements in Telegraph-Transmitters, of which the following is a specification.

My invention relates to means whereby a comparatively inexperienced person is enabled to rapidly and accurately transmit telegraph-messages such as are now transmitted by means of the Morse key.

The object of my invention is to providea transmitter which has a key-board similar to and adapted to be operated in a like manner to that of a type-writer key-board.

My invention consists in a bank of keys such as are employed on the Remington, Yost, or Caligraph type-writer, spindles adapted to be successively operated by means of said keys, a circuit-closing device arranged in connection with each of said spindles and adapted to make contact when operated with a plate or series of plates normally insulated therefrom, whereby the circuit of the instrument is successively closed as several keys are depressed, and signals corresponding to the usual dot-and-dash signals sent over said circuit.

My invention consists, further, in various details of construction and in combinations hereinafter described, and particularly pointed out in the claims.

My invention will be more readily understood by reference to the accompanying drawings, in which- Figure 1 is an end elevation of an instrument embodying my invention, portions of the same being broken away 011 the line a; of Fig. 2. Fig. 2 is a partial plan view of the same, a portion of the instrument being sectioned on the line y of Fig. 1. Fig. 3 is an isometric detail view showing a plunger and its guides. Fig. 4 is a detail sectional elevation of a modified form of circuit-closer hav-' inga tnbularguide. Fig. 5 is a detail of the contact-stud employed in the plunger.

My invention consists, primarily, in providing a number of contact-plungers each provided with a metal stud, with which the metal spindle or key upon which said plunger is secured and by which it is adapted to be operated is adapted to make contact when said spindle is positively operated. In connection with the plunger provided with each key are suitable guides adapted toret-ain the plunger in lateral position, though allowing it to move longitudinally. A suitable wipingbrush or contact-roller is provided on the stud of the plunger. In the path of this brush or roller are provided a series of copper plates of varying sizes, representingthe dots and dashes making up the signal of the particular letter or phrase. The arrangements and sizes of these plates vary in the guideways of the different plungers to correspond to the dot-anddash indication of the letter upon the key of each particular plunger. The stems or spindles are all connected with one terminal of the line, while all of the copper plates are connected with the other terminal. Now when one of the keys is pushed down it is seen that the stem will be forced into contact with the stud in the plunger, thus moving the plunger and forcing its contact-brush across the copper plates provided in the guideways in series, thereby repeatedly making and breaking a circuit with a duration of contact on the several plates directly in proportion to their respective widths. The key then being released is quickly drawn back by a spring provided in connection therewith. At the instant of the release of the key the stem is drawn away from contact with its plungerstud, thereby preventing theretransmission of the signals in reverse order by the passing of the brush back over the copper plates. As the several keys are successively pressed down the desired words are spelled out and the sentence is formed.

As shown in Figs. 1 and 2 of the drawings, the keys 2 are arranged in banks, following in thisrespcct the arrangement of keys on a type-writer. Each key is 'given a separate letter, as shown in Fig. 2, or may be provided with other characters or with phrases. These keys are preferably made of hard rubber and are screwed 011 the upper end of the spindles or stems 3, passing down, as shown, through the hard-rubber or wooden cover 4 and through the brass plate 5. The brass plate 5 makes a close contact with the several stems and formsone terminal of the telegraph-line.

In the lower part of the box made up of the base 6, the sides 7, and the ends 8 I provide a series of guides in which the plungerblocks 9 are adapted to be moved up and down. The plunger 9 consists in the rectangular blocks provided with the central openings adapted to receive the lower ends of the spindles 3, and also the copper studs 10, screwed into the lower ends of the blocks and provided with the contact-brushes 11. A slot 12 is provided in the side of each block, the ends of which are adapted to limit the movement of the pin 13 provided in the spindle 3. A coiled spring Lt is provided around the spindle 3 between the collar 15 thereon and the top of the brass plate 5, whereby the [5 spindle with the key 2 is normally held up in the position shown. In this position the contact-point 16 on the lower end of the spindle 3 is held some distance above the plate 10. The guides shown consist in pairs of hard-rubber strips 17 and 1S, placed on opposite sides of the blocks. These strips are provided with notches 1H and 20 wide enough to loosely admit the plunger-blocks. Thus it will be seen that each plunger is prevented from turning to move its contact-brush out of line with the contacts beneath it. The contactbrush 11 normally bears on the polished hardrubber surface of the strip 18. Beneath the brush in the position shown lie the contactplates 21, of varying widths, representing the dotsand dashes which form the telegra 'ihic signal of the letter printed on the top of the key 2 belonging to that particular plunger. These plates or blocks of copper or brass are fixed permanently in the strip and have hard-rubber insulatingstrips between them and lie in the path of the contact-brush. A different set or arrangement of plates 21 is provided in the path of the contact-brush of each plunger on each stem. As shown,allof the plates are connected by short legs with the wire 22, passing to the metal strip 23, if desired, and thence out through all of the other metal strips and connected with all the other contact-plates 21 to the other side of the telegraph-circuit. Now as a key 2 is pushed down against the tension of its spring l l the contact 16 on the lower end of the spindle 3 will be forced against the top of the stud 10, thus forming a path for the electricity from the plate 5 down the spindle to the stud 10 and the contact-brush 1 1,wh ich path is maintained complete as long as pressure is maintained on the key. As the block 9 is pushed down, the brush 11 is forced at a constant speed across the faces of the plates 21 one after the other. The circuit of the instrument thus completed for an instant, as the brush bears upon the face of the uppermost plate, is then broken as the brush passes onto an insulating strip and then again completed as the brush strikes another copper plate. A pin or strip 25 is brush 11.

position the key is released by the operator removing the finger therefrom. The spindle will now be instantly withdrawn by the spring 14 from contact with the stud 10, the slot 12 being long enough to permit the pin to rise therein with respect to the plate 10, after which the plunger is drawn up to its normal position with the spindle. In this way, by striking successively the different keys, the desired words may be formed and transmitted over the line. The signals at the other end of the telegraph-line may be received after the manner of those sent in the ordinary Morse system.

It is sometimes preferable to leave the back of the plunger free to be gotten at. In this case I may use guides such as are shown in Fig. 3, having the branch or foot 26, extending from the piece 27, corresponding with the strip 18 in Fig. 2. I have also shown in this figure a secondary groove 28, in which the brush is adapted to run, and the side of which prevents the brush from getting out. of line with the contacts 29.

In Fig. 5 I have shown a small thin spring 30 provided on the top of thestud 10, adapted to be screwed into the lower end of the plunger 9, and which is provided with the contactspring 1 l, in this case having the roller 50 in its lower end instead of a simple bend. The spring 30 makes more certain the contact with the spindleS, as a wiping contact is secured instead of a touch contact.

Fig.4 shows a telegraph-key corresponding to one of the keys shown in Figs. 1 and 2, but of a different construction. The plunger 31 is of insulating material and has the interior opening in which the stationary stud is provided, and down against which the head on the lower end of the spindle 35 is adapted to he forced. The plunger is provided on the square spindle 35, so thatit cannot turn thereon, the spindle being held in the brass cross pieces 36 and 37. The tubular guides for the plunger are formed by the cylindrical tube 258, within which the plunger is adapted to move, and in the side of which the contacts 39 are insularly provided. The contact-brush 40 is adapted to press on these plates 39 when the plunger is depressed through the medium of the key, the head of the spindle S5 pressing down on the stud and acting against the force of the coiled spring 41. In applying these keys to an instrument the tubes 38 are screwed into a plate t2 common to all of the tubes and connected with one terminal of the telegraph-line.

I sometimes prefer to make the plungcrs of metal, in which case the stud 10 is insulated from the rest of the plunger.

It is obvious that the contacts of the in strumcnt might be changed about, so as to be used in a system in which the signals are made by breaking the circuit, and, further, that the keys need not be secured directly on the spindles, but that movement may be com mnnicatcd to the spindles and plungers through any desired or convenient arrangement of levers.

Many slight changes would readily suggest themselves to one skilled in the art. It is obvious that such changes might be made without departing from the spirit of my invention, and I therefore do not confine myself to the exact construction shown and described.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The combination, in a telegraph-trans mitter, of a plunger with a spindle adapted to move therein and through the medium of which said plunger is adapted to be moved, a contact-stud provided in said plunger and adapted to make contact with said spindle when said spindle is moved positively, a contact brush or point extending from said plate, and a secondary plate or series of plates arranged in the path of said brush and adapted to make contact therewith when said plunger is operated, whereby, said spindle forming one terminal of an electric circuit and said secondary plates the other terminal, said circuit is closed upon the operation of said plunger.

2. The combination, in a telegraph-trans mitter, of a series of circuit-closers adapted to be operated by keys upon a suitable key-board, said circuit-closers consisting each in a plunger, aspindle upon which said plungeris loosely secured,acontact-stud upon said plunger with which said spindle is adapted to make contact,

a contact device provided on said stud, and

aplate or a series of plates normally insulated from said contact device, but adapted to make contact therewith when said spindle is operated to move said plunger, substantially as described.

3. The combination, in a telegraph-transmitter, of a series of circuit-closers adapted to be operated by keys upon a key-board similar to that of a type-writer, each of said circuitclosers consisting in a spindle provided with a spring, against the force of which said spindle is adapted to be operated, a plunger-head upon said spindle, a stud on said plunger with which said spindle is adapted to make contact when operated, a contact device extending from said stud, guides wherein said spindle and said plunger are adapted to move, and a plate or series of plates rcprpsenting dots and dashes, and with which said contact device on said plunger is adapted tomake contact when said spindle is operated through the medium of one of said keys, all of the spindles of the several circuit-closers forming one terminal of the telegraph-circuit and all of the plates or series of plates forming the other terminal of said circuit, substantially as described.

4. The combination, in a device of the class described, of a spindle with a plunger provided with a stud with which said spindle is adapted to make contact, a tubular guide wherein said plunger is adapted to move 1ongitudinally, a contact device extending from said stud, and a secondary plate or series of plates provided in the path of said contact device, but normally insulated therefrom, said tubular guide forming one terminal of the circuit 111 which said device is included and said secondary plate or plates forming the opposite terminal of said circuit, substantially as described.

5. The combination, in a telegraph-transmitter, of the spindles 3, having the keys 2, the metal plate 5, the springs let, plungers on the lower ends of said spindles, the studs in said plungers, said spindles adapted to make contact with said studs when forced down, said plungerbeing adapted to move longitudinally on said spindle and being at all times retained thereon, guides adapted to retain said plungers in lateral position, contactbrushes extending from said plates or studs, and secondary plates and series of plates provided in the paths of said brushes and adapted to make contact therewith as the keys are successively depressed, all of said secondary plates connected together to form one terminal of the circuit in which the transmitter is included and said plate 5 forming the opposite terminal, substantially as and for the purpose specified.

In testimony'whereof I have hereunto set my hand this 26th day of November, 1890.

A. M. GASKILL, C. G. HAWLEY. 

